1. Field of the Invention
The present invention relates to an antiglare mirror for an automobile, which mirror may be advantageously used as a rearview mirror or side mirror.
The term "color tone", used throughout the specification, means the perspective evaluation of a color determined by both the lightness and the saturation of the color.
2. Description of the Related Art
Usual mirrors for automobiles consist of a glass substrate on which aluminum is deposited by vacuum evaporation. Such mirrors have a reflectivity as high as 80% to 90% and a relatively flat spectral characteristic. As a result, drivers of automobiles are often temporary blinded by the glare caused when the sun shines behind them in daytime or by the lights of vehicles behind them at night.
In order to eliminate such annoyances, there have been proposed mirrors in which a liquid crystal is used for preventing glare, such as disclosed in Japanese Examined Patent Publication (Kokoku) No. 48-35384. While various types of such mirrors have been proposed, none include the additional feature, enhancing the commercial value of an automobile, by satisfactorily coloring the reflected light.
If an antiglare mirror as mentioned above is colored by a light absorption type color filter or a colorant, the resultant colored light has inferior clearness or brightness. Also there is a problem of discoloration with time. Further, when a colorant is added to a dynamic scattering mode (DSM) liquid crystal, which is used to ensure appropriate reflectivities both when preventing glare and not preventing glare, the coloring effect disappears when glare is being prevented since the DSM liquid crystal becomes cloudy and white at that time.